They really are different devices, I've not thought of them as competitors for over a year now.

I agree; the Sony is a dedicated bookreader; the iLiad is a general-purpose computer.

The reason I plan to buy a CyBook (when it becomes available) is because I want an equivalent of the Sony which will handle MobiPocket format, so I can use the same book format on both a highly portable device like the CyBook and a larger-format one like the iLiad.

I share your view that the devices are complimentary rather than "rivals".